Electric meter



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` C. IVI. WILD.

A ELEGIR-sc Meren APPLICATION FILED DEC. I2. 19I4.

Patented' J une 2?, 1916.A

' Mmmm?.

20 n burned out or damaged. Y' These occurrences'-v EDjsTATEs PATENT oEEroE.

CHARLES M. WILD, o'E SPRINGFIELD,l MAssAcHusE'rrs,` .issrGNoE 'ro'.BoscH MAGNET() 1 ooMPANY, o E NEW YORK, N. Y.,

A coRPonn'rIoN or NEW YoRK.

ELECTRIC METER.

To aZZIwVLom t muy conccmqi v, l ,l Be it known that'I, CHARLES M. WILD,

a subject of the 'Emperor of Germany, re-

' siding at-No. 14 Springfield street, Springield, county of Hampden, 'and State of I Massachusetts have` invented certain new' and useful Improvements in -Electric 'Meters; and I dovhereby declare the following to be a full, clear, and exact descrip ion' of th'e invention, such as will enable others skilled inthe art to lwhich it appertains to i 4make and use the same., l*

In' ammeters for direct current electriccircuits, itis customary to provide-'a current.

'shunt for the deflectingcoil and this 4shunt carries substantially all the current to vbe measured. In case of a -la-rge current flow dueforinstance, to a short circuit on the system, the 'shunt may be fused or otherwise vdamaged and the deflecting coil alsowill be are particularly likely on automobiles'or .motor-boats on account of the vibration and shockto which the equipment is .continually subjected. i. n

' One object of the present invention-iste safeguard the meter against action` of ab# normally large currents, and I obtain this object by providing a switch which normally short circuits the current shunt and therebyv carries substantially all the current except I when the Operator opens the switch to .obtain terminals ofthe. current shunt, the meter v then indicating the current strength; and such that, in the-other position of the switch,y one terminal of the delectingc'oil is disconnected from the current shunt and connected to a resistance coil, which is connected to the other side of the circuit,the meter thenindicating the Voltage. of the system.

- In accordance with my invention, the mechanism l which .operates the switch to.

lchange. over the meter, also' operates the switch which short circuitsv thecurrent Y,

shunt, vand preferably the switch-operating mechanism is normally Iheld 'by a spring 'to the other side b of the circuit.

.y atentea Jane 27,19j16r; Application filed :Decembel 12: 1914- Srial-No- 876,833-

vprotected bythe short circuitinglswitchand wherein the' deflecting coil is connectedv to' the resistance coil tov4 indicate voltage. In the accompanying drawings illustrating my 1nvention,"'Figure"1 is a." side ,eleva.

' tion, partly in'secti'on, with the easing oflthe lmeter removed toparticularly. show the switch operating mechanism; Fig.' 2 is :a

lsimilar view particularly showing thecurrent shunt and the short circuiting switch therefor.; Fig. 3 is atrontl view'of the meter;-

Fig. 4 is a rear view'of the meter; and Fig;

5..-is a diagram of connections.

The meter comprises'a' permanent magnet; 1 -of the horse shoe type, acentral zero scale 2, anda deflecting coil `with the pointer' 4, all inclosed in 'thecasing 5 and constructed in-'the well known way.v The'currentV shurt -6 is mounted on the-back of the casing an lhas two terminals 7 and 8 for connection in` onefside a ofthe circuit. The" switch9 is-,

fastened to the terminal'7 and is composed.v

of spring metal tending to engage the terminal 48. The switlchhas aprojecting end-'1Q'.v

with v which'coperatesja' push rod 1-1","in`'""` sulated at 12 from the switch, and at 13 :t'roini the cam 14. The handle ,'15 carrying the cam" isarranged 0n thefront of the casing and .is held by the spring 20. in that position shown in the drawlngs wherein the `switch V9 is closed .to short circuit the current shunt 6.

One terminal of they deflecting coil 3 is, connected by an insulated wire, to the terminal 7 of the 'current shunt and the other terminalofi l the deiiecting. coilf is permanently connected vvto the -switch tongue 16 of springmetal which tends to engage the j' contact 17 connected to one terminal ofthe -95 resistance coil-18. The other `terminal of this coil is connected to the other side b of the circuit, '01T is groundedon the casingv of the meter in casethe meter is to be used in a grounded system. Thus, when the parts `have the position illustrated,the meter indi;

cates the vvoltage ofthe circuit, the .connecf tions being from the side a of the circuitl through terminal 7, 'deflecting coil 3, switch tongue 16, contact 17l and resistance coil 18 When it is desired to indicate the current in the circuit, the 'handle 15 is turned about- 90 in the direction of the 'arrow 1n Fig. 3,

whereupon the rising part of. the cam 14 depresses the push' `rod` 11, opening the shortv 1.10

en 'i v i' eircuitin` sii'itch and pressing; the switch tongue 16 into engagement with the corr tact 19 on the Vterminal Se rlhe detlectingg coilis then connected directly across the terminals of the current shunt '5, through whichy substantiallyall 'of the current then flows. When the handle is released, the spring 2O returns it to that position wherein the meter indicates the Volt-age of the system and wherein the current shunt is short circuited and thereby protected by the" switch 9. Having thus described my invention, vwhat I claim is:

' '1 -'In an velectric meter, adetlecting coil carrying an indicator, a current shunt for said coil, and a switch" mounted directly on the currt-Bnt shunt, one end ot said switch being' fastened to one terminal of the cur- "rent'fshunt, and the other end of the switch vbeing 'engageablfei with the otherv terminal of the current shunt.

ln an electric meter, a deilecting coil carrying an indicator, a current shunt :tor i said coil. a vswitch mounted directly on the current shunt and embodyingr a spring blade fastenedy at one end to one ,terminal of fthe current shunt sol that its other end tends constantly to engage the otl'ier terminal of :sie

the current shunt, and ,operating mecha-A ni'sin'I for holding the'treeend ofthe spring blade out ofengagement with the terminal of the current shunt;

i l, lin an electric'meter, a defl'ecting coil cluding a current shunt for' vsaid coil adapting the meter for indications ot ci'irrent strength, 'a switch normally short circuiting *he current shunt; circuit connections carrying an indicator, circuit connections in 'f 35 meter for indications of'voltage, said lever haring a single other operative position-1n which position the switch is held out of short'circuiting position and the circuit conl'and switch operating mechanism which in one position operates the first mentioned switch to connect the deilecting coil to the resistance coil to obtain an indication of voltage, and which i'n a second position connects'the detlecting'coil across thecurrent shunt and opens the short circuiting switch to obtain an indication ot current strength. 5. ln Aan electric meter, a detlecting coil carrying` an indicator, circuit connections including' a resistance for adapting' the meter 'to indicate Voltage, and other circuit connections includii'ig a current shunt to adapt the meter to indicate current-strength, a short ci-rcuiting switch for ythe current shunt, operating, mechanismykoperative with said circuits to change over-"themme't'er `from one to anotherfof'said indications, and a spring tending to .hold 'the operating mechanism in that position in which the meter indicates voltage and in which the current shunt is short lcircuited by the switch.5

In: testimony whereof I attix my signature in presence ot two witnesses.

CHARLES lil. XVLD.

lilitnesscs: y i Anim Scrrwiiiz,

ltoLr LiNnnNimrN. 

